Today's evolvement of different types of communication networks is very fast, as well as the different kinds of services that are supported by these different communication networks and thus offered to users of the different communication networks. Often, different types of communication networks are interconnected and used jointly to support various end-to-end services.
A connectivity service provides data communication between two or more entities via a transport network. The transport network itself may rely on e.g. Multi Protocol label Switch Transport Profile (MPIS-TP), Carrier Ethernet and Optical Transport Network (OTN).
In order to ascertain that a transport network is functioning properly and to detect any faults, excessive loads etc., the networks are most often monitored and supervised. This is normally referred to as Operation, Administration and Management (OAM) and this term is also used to describe processes, activities, tools, standards for operating, administrating, managing and maintaining transport networks and connectivity services. Different standards are used for OAM depending on, for example, the technology used for the connectivity services and the transport network.
For Ethernet transport networks, two available standards are ITU-TY.1731 and IEEE 802.1ag. These standards define fault management and performance monitoring in Ethernet networks. Different parameters may be measured for this purpose, such as frame loss ratio, frame delay and delay variation. Measuring these different parameters assists with Service level Agreement (SIA) assurance and capacity planning. Regarding fault management, the common standards include functionality for continuity checks, loopback measurements, link traces and alarm suppression.
Different connectivity services can have different SIAs, depending on the type of service and the requirements of the customer. Depending on the specific service, different parameters have different importance. Speech, for example, demands very low delay and jitter (delay variation), whereas for data communication delay typically is of less importance and capacity of higher importance. So, different parameters are important to measure for different services.
For IP transport networks, one available standard is RFC 792. This standard defines the Internet Control Message Protocol which is an OAM protocol for IP-based networks. It provides functionality for packet delay, packet round-trip and packet loss measurements. It also has capabilities for tracing the route between hosts in a similar way to the Ethernet link trace function defined in ITU-TY.1731.
Each network technology defines a set of performance parameters to be measured for OAM purposes. Some examples of such performance parameters again are, delay, delay variation, loss, jitter and capacity for defining SIA performance parameters. Both the parameter definition and naming may vary depending on the standardization body, i.e. the organization in charge of the various standards. Some examples of such organizations are the Metro Ethernet Forum (MEF), International Telecommunication Union (ITU-T), Institute of Electrical & Electronics Engineering (IEEE) and Internet Engineering Task once (IETF). As a consequence, there exist a vast variety of parameters, some being similar in name and definition, but still somewhat different Even one and the same parameter may have different names in different standards.
Different operators also provide different connectivity services. It is not unusual for an operator to provide thousands of different connectivity services, in the future also hundreds of thousands different connectivity services, all having different SIAs. As a result, it becomes very complex indeed to keep track of which parameters are available for each service, and what the acceptable intervals are for each parameter. By an acceptable interval is meant the values a parameter may have to fulfill an SIA for the parameter in question. Further, different tools are used to measure different parameters. Not only does an operator need to keep track of all the various parameters, the operator also needs to know which tool to use for measuring a specific parameter according to different standards. The parameters, the OAM functionality and the measurement tools are technology dependent while the SIA and acceptable intervals are dependent on the specific connectivity service.